1. Field of the Invention
The invention relates to a multispectral sensor, in which different spectral ranges of a radiation to be measured are determined.
2. Background of the Disclosure
Such sensors make it possible to carry out accurate temperature measurements, because through measuring in different spectral ranges it is possible to largely compensate the influencing of the measurement result by widely differing emissivities in different spectral ranges.
In order to obtain a precise picture of the spectral range of the radiation to be measured, it is necessary for an identical test beam to be supplied to the channels for different spectral ranges.
Various multispectral processes are known, which in particular differ through the methods of spatial and spectral dispersion of the radiation. The use of dispersing optical components, e.g. prisms, particular for the analysis of broad-band spectral ranges, requires a very high adjustment and space requirement. Such processes can consequently not be used for a sensor, which is to be designed as an easily manipulatable, discreet component with small dimensions.
The use of a multispectral sensor as proposed in East German Patent 28 11 04 is fundamentally possible, but as a result of the usable number of pyroelectric materials with the corresponding optical characteristics, is limited to a small number of spectral channels (&lt;4) and corresponding uses.
The use of discrete filters for the spectral dispersion of the total radiation has hitherto only been useful in conjunction with swinging-in mechanisms, e.g. a filter wheel, in the case of a serial readout of a single-component sensor, or as a planar arrangement of individual filters in juxtaposed or continuous manner on a substrate.
The disadvantage of the first variant is inter alia the varying measurement spot in the case of moving objects and the time superimposition of the output signals in the case of serial readout with simultaneously reduced sensitivity. The second variant leads to different measurement spots and is consequently unusable for precise measurements.
Thus, the hitherto known multispectral measuring devices have both a large material and space requirement and also a considerable adjustment effort is required. This in turn leads to mechanical instability and to limited local resolution of the measurement.